Risk Management and Hedging Activities - EEGH - Narrative (Details) - customer	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
EGTS
Derivative [Line Items]
Number of customers serviced	252
Revenue | Customer concentration risk | EEGH | Export customers
Derivative [Line Items]
Concentration risk, percentage	39.00%	38.00%
Revenue | Customer concentration risk | EEGH | Eastern Energy's largest customer
Derivative [Line Items]
Concentration risk, percentage	20.00%	19.00%
Revenue, product and service | Customer concentration risk | EGTS | Storage and transmission | Directly to consumer
Derivative [Line Items]
Concentration risk, percentage	95.00%
Revenue, product and service | Customer concentration risk | EGTS | Ten largest customers | Storage and transmission
Derivative [Line Items]
Concentration risk, percentage	41.00%
Revenue, product and service | Customer concentration risk | EGTS | Thirty largest customers | Storage and transmission
Derivative [Line Items]
Concentration risk, percentage	72.00%